Personne :
Hernández, Roger

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Hernández
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Roger
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Université Laval. Département des sciences du bois et de la forêt
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ncf10295022
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  • Publication
    Accès libre
    Shrinkage variation in Japanese larch (Larix kaempferi, [Lamb.]) progenies/provenances trials in Eastern Canada
    (Taylor & Francis, 2017-05-19) Caceres Cuadros, Claudia; Fortin, Yves; Hernández, Roger
    Twelve-year-old Japanese larch (Larix kaempferi [Lamb.]Carr.) trees of 20 different progenies and/or provenances were sampled at one site in the Mauricie region of Quebec. Two standard samples were obtained at breast height and closer to the bark from each tree. Partial and total radial, tangential, and volumetric shrinkages, and tangential/radial (T/R) shrinkage ratios were assessed. All of these variables were significantly affected by the progeny/provenance. Drying defects are one of the main reasons for downgrading larch lumber; thus, T/R shrinkage ratio was considered for the selection of progenies/provenances for lumber production purposes. Lowest partial and total T/R shrinkage ratios were obtained with progenies/provenances 8964, 8904, 8962, 8957, 8907, 8927, 7283, and 7795. Among them, lowest partial and total tangential, radial, and volumetric shrinkages were found in progenies/provenances 8964, 8962, and 8907 as well. Other physico-chemical (mechanical properties, density, extractive content) and silvicultural (growth rate) attributes should also be taken into consideration for an adequate selection of progenies/provenances according to the specific final utilization.
  • Publication
    Accès libre
    Variation of the physical and mechanical properties of hybrid poplar clones
    (Dept. of Wood and Paper Science College of Natural Resources North Carolina State University, 2014-01-01) Huda, Azmul; Cloutier, Alain; Koubaa, Ahmed; Fortin, Yves; Hernández, Roger
    The physical and mechanical properties of poplar clones largely determine their suitability for various end-uses, especially for high value-added applications. The main objective of this study was to determine the clonal variation of selected physical and mechanical properties of seven hybrid poplar clones grown at three sites in southern Quebec, Canada. Five trees per clone were randomly sampled from each site for wood properties measurement. Site had a significant effect on all measured properties except radial shrinkage. All properties of hybrid poplar wood showed significant interclonal variation, indicating the possibility of identifying clones with superior wood properties, especially for density, flexural modulus of rupture, and ultimate crushing strength. High heritability values for the studied properties indicated that these properties are under moderate to high genetic control. The genetic gain for these wood properties ranged from 2.0% to 13.5%.
  • Publication
    Accès libre
    Phenotypic and genotypic correlations for wood properties of hybrid poplar clones of southern Quebec
    (Molecular Diversity Preservation International, 2018-03-15) Huda, Azmul; Périnet, Pierre; Cloutier, Alain; Koubaa, Ahmed; Fortin, Yves; Hernández, Roger
    This study aims to understand the phenotypic and genotypic correlations among wood anatomical, physical, and mechanical properties of hybrid poplar clones. Samples were taken from seven clones grown on three sites in Southern Quebec, Canada. Five trees per clone were randomly sampled from each site to measure anatomical (fiber length, fiber proportion, vessel proportion, fiber wall thickness, tension wood), physical (basic density, volumetric, longitudinal, tangential, and radial shrinkage), and mechanical wood properties (flexural modulus of elasticity (MOE), modulus of rupture (MOR), ultimate crushing strength parallel to the grain). The observed phenotypic and genotypic correlations between these wood properties were moderate to strong, except for fiber length and vessel proportion. Genotypic correlations for all wood properties were higher than for corresponding phenotypic correlations. Furthermore, fiber length showed weak correlations, whereas, vessel proportion showed strongly negative correlations with all other properties. Strong correlations were also found among fiber proportion, fiber wall thickness, basic density, and mechanical properties. Furthermore, results from this study show close genotypic and phenotypic correlations between fiber proportion, fiber wall thickness, and wood density, which consequently affect the mechanical performance of wood products. These findings indicate that there is a substantial opportunity to improve wood quality by selecting several wood properties for different end uses.